This is an image from E3D showing a pathologically bad hot end, literally covered in black deposits. This corruption is almost mandatory for 3D printers, as thin strands of extruded plastic somehow make their way above the plane of printing and land on the hot nozzle.

A badly corrupted hotend beside a new unit

Once they’ve hit the nozzle, they’re not going away unless you immediately wipe them off while in hot, malleable form. Sometimes wiping makes it worse by pushing the lost plastic into nooks and crannies where it’s even more challenging to remove it.

Eventually this stuff blackens as it is repeatedly subject to the full temperature range of the hot end during printing operations.

So is this merely a cosmetic issue? Certainly blackened hot ends are not attractive and suggest a poorly maintained machine. But there are practical issues with these deposits, too.

E3D's silicone hotend sock product covers up every part of the 3D printer hotend except the nozzle

This is what happens: at an unpredictable time, usually during the longest-duration prints in white or bright material, a small fleck of those deposits will decide to drop into your active print, immediately fused permanently into the model.

Unless you plan on painting your models or don’t care about the looks, your print is essentially ruined.

Sometimes it’s totally obvious, as in the orange print above, but other times it’s quite subtle, like this small black mark above Donald’s lip. (Aside: Why didn’t I print Donald in orange?)

Anyhow, E3D seems to have mostly solved these issues with their new “HotEnd Socks”. They are a custom-fit silicone wrapper that precisely matches their E3D-v6 hotend.

The socks are made from a specific mix of flexible silicone able to withstand the high temperatures involved.

They are easily installed and removed, which you will periodically do to remove any accumulation of plastic. It just peels off because they’ve ensured the silicone does not adhere to commonly 3D printed materials.

The blue color also makes your machine a bit more attractive, too.

E3D has the socks available in sets of three for the ridiculously low price of £3.50 (USD$4.60). However, note that these are fitted only for the E3D hotend, and the company is highly unlikely to produce versions for other hotends. But that may not stop others from doing so, and I could see a very small business making models for at least the most popular desktop 3D printers.

Kerry Stevenson, aka "General Fabb" has been writing Fabbaloo posts since he launched the venture in 2007, with an intention to promote and grow the incredible technology of 3D printing across the world. So far, it seems to be working!

Fabbaloo is a daily online publication focusing on the 3D print and additive manufacturing industries. We provide deeper analysis of developments in current and future technologies as well as corporate matters. If there’s something happening in 3D technologies, especially FDM, SLA, SLS and Stereolithography, we’ll have an opinion about it.